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Kari Fluegel April 5, 1993

Release No. 93-025

STS-56 ASTRONAUTS TO DOCUMENT EARTH OBSERVATIONS

Low Earth orbit gives space shuttle astronauts a unique vantage point from which to observe and document a variety of meteorological, atmospheric, geological and oceanographic features for scientitific researchers back home.

STS-56 will add to the vast collection of Earth observation photographs that have been taken throughout the space program. The eight-day mission will orbit at an altitude of about 160 nautical miles and an inclination of 57 degrees, taking the astronauts over about 80 percent of the Earth's surface.

The photographic documentation of Earth observations is dependent on several factors including weather, lighting and crew activities. A change in the launch time would affect the daytime lighting conditions at planned observation points. Steering maneuvers may turn orbiter windows away from the Earth. Crew activities with higher priority often are rescheduled during missions, thus precluding planned Earth observations. Clouds also frequently interfere with the planned photography.

Still, Earth observation is a favorite activity for astronauts, and crew members usually return from their space missions with hundreds of photographs and thousands of feet of film. A large assortment of cameras, lenses and films are carried on each shuttle flight, and astronauts participate in a series of science training sessions prior to their mission so they can optimize the limited observation time. The STS-54 crew members, for example, took more than 1,600 photographs on their six-day flight in January including the documentation of a thermal upwelling in the Pacific (which could indicate the formation of an "El Nino" effect on weather patterns) and the photographing of highland gorilla habitats in Central Africa.

During STS-56, astronauts will use different cameras with a wide variety of lenses and filters. They also have almost 100 rolls of films onboard Discovery and could bring back as many as 5,500 photographs. The 57-degree

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inclination and night launch will give crew members the opportunity to photograph areas in the southern oceans rarely seen by shuttle astronauts including the Chatham, Bounty and Antipodes Islands of the South Pacific, Iles Crozet and Heard Island in the Indian Ocean, and Bouvetoya and the South Sandwich Islands in the South Atlantic. Crew training for this task has consisted primarily of reviewing maps since, in the majority of cases, there are no representative photos in the Space Shuttle Earth Observations Project database. In addition, many of the islands are small and will be difficult to spot from the orbiter.

Other Earth observations may include photo documentation of river deltas and distributary channels, deforestation, land use, internal ocean waves, geologic structures and environmental change. Planned photo opportunities include

Mississippi River Delta, Louisiana -- Coastal Louisiana was created by the Mississippi River sediments. The river has shifted course six times in the last 3,000 years. After each shift, the river abandoned an aging, deteriorating delta and built a new delta, each time adding land to the coastline. The Mississippi River's future route to the sea is the Atchafalaya River. The Mississippi River began building a new delta at the mouth of the Atchafalaya River in the mid-19th century. After the great 1927 flood, the Army Corps of Engineers intervened with the construction of the Old River Control Structure and other ancillary structures to contain the Mississippi and allow no more than 30 percent of its flow into the Atchafalaya Basin. Even so, the Atchafalaya Delta continues growing and providing sediment that is rebuilding the Chenier Plain along the Western Louisiana coast. Many researchers believe nature will win; the river will ultimately change its course. Photos taken from the shuttle will provide scientists with an opportunity to document and monitor the death and birth of major deltas.

Aral Sea -- The Aral Sea is a high priority target for Earth-observing scientists. The sea is fed by two rivers -- the Amu Darya and the Syr Darya -- which pass through a large desert area that has been turned into irrigated farmland. Consequently, a large portion of the sea's incoming flow has been diverted causing Aral Sea water levels to drop significantly. Islands are rising from the sea and have split it into several separate water bodies. Numerous problems have arisen as the water levels have dropped. For example, a fish processing factory which was once on the banks of the Aral Sea is now 80 km from the beach. Trainloads of fish now are transported from the Pacific Ocean to keep the factory open and the surrounding community productive. Also, as the Amu Darya and Syr Darya flow through the farmland, they collect

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agricultural chemicals which then are deposited into the Aral Sea. As these chemicals have moved into the sea and surrounding area, soil fertility has decreased and human health problems have increased in the area. Cancer rates and birth defects are up. Several joint US/Russian science teams are studying the death of what was once the fourth largest lake in the world. Shuttle photography will contribute to the research being conducted on the area, which can be considered an analog to other irrigated agricultural areas around the world.

Parana River Basin, Paraguay Argentina -- As a new frontier, the central Parana River Basin has become the focus of an expanding development effort by Argentina and Paraguay. It holds particular interest as a region of rapidly changing land use and thus also of the problems associated with such development. The lumber industry is clearing forests, and farm plots are replacing pastures. Problems associated with land use changes include accelerated soil erosion and the corresponding silting-up of reservoirs, dams and streams. With time, sediment from these areas could well induce devastating changes as stream channels straighten. Low elevations in the basin experience widespread seasonal flooding from the large Parana, Paraguay and Uruguay River systems. Dams and bridges are planned which may alter present patterns of flooding and sedimentation in these rivers. Photographs of present natural and man-made patterns permit the establishment of baselines from which to measure environmental change.

Flores Island, Lesser Sunda Islands, Indonesia -- In December 1992, an enormous tsunami hit Flores Island sending 80-foot waves onto the island and killing 2,500 people. At the request of the National Oceanographic and Atmospheric Administration, shuttle astronauts will be photographing the island extensively to document debris lines, scarring and vegetation damage caused by the storm.

Central Equatorial Pacific Ocean -- The United States oceanographic community currently is involved in a large, multi-national research effort to understand global biochemical cycles. The focus of this research effort soon will turn from the North Atlantic to the Equatorial Pacific Ocean. The Equatorial Pacific Ocean is believed to play an important role in the annual global uptake of atmospheric carbon dioxide by the oceans. In addition, other researchers are interested in the Equatorial Pacific Ocean as a short-term predictor of El Nino. An interesting characteristic of the Equatorial Pacific Ocean, as depicted in shuttle photography, is the presence of long shear lines or suloys (areas of chaotic waves), generally in a north-south orientation.

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These shear lines are believed to the boundary between two different water masses, perhaps differing in temperature and perhaps related to the nearly constant upwelling of cold water that takes place at the equator. These features can only be seen in the sunglint pattern and often only after the flight when photographs are developed and analyzed. Space shuttle photographs of dynamic features on the surface, seen in the sunglint pattern, will aid scientists in understanding the ocean physical processes at the equator and the role they play in short-term and long-term climate change.

Northern China -- During STS-41D, astronauts documented a large duststorm north of Hawaii. Scientists subsequently determined that the dust was blowing eastward from the Gobi Desert of China and Mongolia. Such duststorms are neither well understood nor well documented; however, researchers believe it is extremely unusual for duststorms emanating from Asia to travel almost to North America. Astronauts on three shuttle missions since 1988 have noted large duststorms over Korea and Japan. Their photographs have shown that the dust was so thick that crew members looking straight down were unable to determine if they were over land or over the Pacific Ocean. Meteorological reports from China indicate that another storm may be forming. Shuttle photography will increase provide new data points to analyze this environmental phenomena.

Macquarie Island -- Macquarie Island is hypothesized to be located at or near the junction of three tectonic plates: Indo-Australian, Antarctic and Pacific. This little-known island is not well-mapped, so views photographed from the space shuttle will be valuable in identifying geologic structures and related vegetation patterns. Presently, there are no photographs of Macquarie Island in the Space Shuttle Earth Observations Project database.

Lake Chad, Niger, Nigeria, Chad, Cameroon -- Lake Chad lies in a large basin of internal drainage which is located in the center of the Sahel. During periods of adequate rainfall, runoff accumulates in the basin, filling Lake Chad and permitting extensive agriculture and local fishing. When first photographed from orbit during Gemini 9 in 1966, the lake surface covered 25,000 square kilometers. Long-duration droughts from 1968 to 1974 and beginning again in 1982 to the present have drastically reduced the size of the lake. Open water now covers only 2,500 sq. km of the southern portion of the lake bed. The declining lake level has rendered expensive irrigation projects useless. Where villagers once fished, the surviving inhabitants now practice slash-and-burn agriculture on the lake floor. The position of Lake Chad and the sensitivity of the lake to changes in regional rainfall make the site an ideal

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focus for drought impact studies using satellite radiometer data and astronaut photography. Photographs illustrating the current status of the lake are sent directly to monitoring groups working in the region for comparison surface surveys.

Okavango Basin, Botswana, Zimbabwe -- The Okavango Basin is one of the wilder, less spoiled regions of Africa. With the stable government it has enjoyed, Botswana stands a good chance of preserving its rich and unique natural habitats at the same time as a host of new economic developments are introduced. Part of the enormous swampland of the inland delta of the Okavango River has been set aside as a nature reserve, as have five areas in the neighboring dry semi-desert. The area is one of few remaining regions in Africa which still supports great herds of elephant, wildebeest, zebra, impala and the Cape buffalo. Despite conservation efforts, habitats in the "Green Jewel," as the Okavango is called, are being pressured by demands for land for grazing and water for mining. Hand-held photography will continue to aid on-going monitoring of the fragile desert biome as these developments continue to alter the face of the Okavango Basin.

Following each mission the people working on the Space Shuttle Earth Observations Project catalog each photograph for an electronic data base which is used by hundreds of researchers. These scientists also describe and analyze many of the photographs for scientific colleagues, students and the public.